1. Field of the Invention
The present invention relates to N-(4-oxo-butanoic acid)-L-amino acid-ester derivatives, in particular to the preparation method and application of N-(4-oxo-butanoic acid)-L-amino acid-ester derivatives.
2. Description of the Related Prior Art
Recent years, with increase in average life expectancy of population, an advanced aged society had developed. Hypertension is one of the most common vasocular diseases within this group of people. As a consequence of this trend, medicines for reducing blood pressure had become even more demanding than before. Among all the drugs, ACE (Angiotensin Converting Enzyme) inhibitor is one of the drugs used for treating hypertension and heart failure. Unlike other drugs used for hypertension treatment, ACE inhibitor will not result in common side effects, they do not have central nervous system side effect. Moreover, ACE does not cause harmful interference with metabolism where diuretic does, it is also suitable for the population who suffers from asthma or diabetes, and therefore it is highly appreciate by the patients. The related kinds of reducing blood pressure medicines that had already been disclosed in U.S. patents are U.S. Pat. No. 4,542,234, Pat. No. 4,465,443, Pat. No. 4,480,874, Pat. No. 4,879,403, Pat. No. 4,925,969, Pat. No. 5,756,812 and Pat. No. 6,118,010.